1. Field of the Invention
The present invention relates to an apparatus and a method for assigning a Mobile Station IDentifier (MS ID) in a wireless communication system. More particularly, the present invention relates to an apparatus and a method for forming and assigning an MS ID including neighbor base station information in a wireless communication system.
2. Description of the Related Art
In a wireless communication system, a base station and a mobile station identify a service connection using a Connection IDentifier (CID). For example, in a communication system using the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, when an initial setting is completed, a base station and a mobile station generate CIDs having 16 bits such as a basic CID and a primary management CID. Also, in case of providing a new service, the base station and the mobile station generate a transmission CID for a new service connection. After that, to identify resource assignment information for a specific mobile station, the base station forms a MAP to include a basic CID of a relevant mobile station. For example, the base station forms a downlink MAP to include a CID of a mobile station as illustrated in FIG. 1.
FIG. 1 illustrates a MAP construction which uses a CID in a conventional wireless communication system.
Referring to FIG. 1, downlink MAPs include a CID of a relevant mobile station in order to identify the mobile station corresponding to resource assignment information of the downlink MAPs.
A mobile station may confirm resource assignment information assigned by a base station using a MAP including a CID associated with the mobile station itself among MAPs received from the base station.
A transmission terminal incorporates a CID representing a service connection into a Media Access Control (MAC) header of data and transmits the data. In this case, a reception terminal may confirm whether received data is data for the service connection assigned to the reception terminal through the CID contained in the MAC header of the data.
As described above, the base station and the mobile station identify a service connection using a CID. Therefore, each CID should have a unique value which does not overlap another CID inside a cell managed by the base station.
In the case where a mobile station performs a handover, the mobile station should replace a CID, which has been used for communication with a serving base station, with a CID to be used for a target base station in order to prevent the CIDs from overlapping. Here, the serving base station denotes a base station accessed by the mobile station before the mobile station performs the handover, and the target base station denotes a base station to be newly accessed by the mobile station through the handover. In this case, the mobile station replaces all CIDs even when CIDs which have been used for the serving base station overlap only some of the CIDs used by a different mobile station in a target base station.
In the case where the mobile station performs the handover, the serving base station transmits CID information, assigned to the mobile station by candidate base stations to which the mobile station may perform a handover, to the mobile station through a handover response message HandOver(HO)-ReSPonse(RSP) in order to update CIDs of the mobile station. Accordingly, the size of the handover response message HO-RSP increases.
Also, the transmission terminal incorporates CIDs into relevant data and transmits the data so that the reception terminal may identify a service connection corresponding to the received data. Accordingly, the CIDs contained in the data act as a fixed overhead of transmission data.